1. Field of the Invention
This invention relates broadly in the field of electronic musical tone generators and in particular is concerned with provision for transferring notes played on an accompaniment keyboard to add to notes played on a solo keyboard.
2. Description of the Prior Art
Electronic musical designers have exploited the mechanical-like tone production implementation of keyboard instruments to provide a variety of ancillary systems to aid the neophyte musician. These ancillary systems have a common object of enabling the new musician to generate tonal effects which usually can only be performed when one has attained a practised dexterity on the keyboard. Such ancillary systems include those of automatic arpeggios, chords controlled in preselected rhythmic patterns, automatic pedal accompaniment played in rhythmic patterns, automatic glissandos, and automatic portamento frequency transitions.
A new keyboard instrument player quickly discovers a satisfaction in playing a simple monophonic solo line on a solo keyboard which is supported by chords played with the left hand on an accompaniment keyboard. Accomplished keyboard instrument players using an organ will augment the solo line of a musical piece by adding notes to an otherwise monophonic solo part. This is usually accomplished by inserting notes on the solo keyboard corresponding to notes belonging to the chords that are played on the accompaniment keyboard. The notes added to the solo part, often referred to as "fill-ins", are usually not scored in the written music. These are provided by the player in an ad lib fashion. The proper selection of fill-in notes requires a musical sophistication on the part of the player that is beyond the capability of the beginning player. It is all too easy to produce objectionable dissonant musical effects by attempting to add fill-in notes to a solo musical line.
Several systems have been developed which add fill-in notes to a keyboard by transferring notes played on an accompaniment keyboard. Such a system is disclosed in U.S. Pat. No. 3,823,246 entitled "Chord Playing Organ Including A Circuit Arrangement For Adding Fill-In Notes To The Solo Part." The patent describes apparatus that in the fill-in mode of operation utilizes the lower, or accompaniment, keyboard of an organ as a monophonic chord input data set of keys. In this mode a single finger is used to actuate a keyboard switch and thereby select a predetermined chord type. The selected chord is sounded for the set of stops, or tone switches, actuated for the accompaniment keyboard. Two notes of the automatically generated chord are transferred to the solo keyboard and the transferred notes are played at the same time that a note is actuated on the solo keyboard. The transferred notes are caused to sound in an octave below the actuated solo note. The two transferred notes are selected from the automatically generated chord by using a selection logic that is responsive to the actuated solo note. In this fashion dissonant harmonic intervals can usually be eliminated. Circuitry is provided to inhibit the chord generating apparatus if more than one note is actuated on the lower keyboard.
An improvement to the system disclosed in U.S. Pat. No. 3,823,246 is contained in U.S. Pat. No. 3,990,339 entitled "Electronic Organ And Method Of Operation." The musical effect produced by the disclosed system is very similar to that previously described for U.S. Pat. No. 3,823,246. A time delay is incorporated so that the fill-in notes are automatically inhibited during the execution of a sequence of "fast" notes played on the solo keyboard.
The present invention provides a novel means for providing fill-in notes for a solo melodic line and incorporates a feature that selects the fill-in notes using data produced by the actuated upper and lower keyboard switches. Both keyboards can be operated in their normal polyphonic mode. The invention includes means for correcting some accidental mistakes such as when almost completely nonsensical combinations of notes are actuated.